This subtle-seeming transition in the structure of circuitry, from serial to parallel, was the grid’s first revolution. Though we tend to give Thomas Alva Edison the credit for having invented the lightbulb (he did not), he did devise something just as remarkable—the parallel circuit, one of his greatest if least lauded contributions to technological underpinnings of our modern world. The very existence of a relatively dim bulb, which we take for granted today, was made possible only by the prior invention of the parallel circuit.
